IN ACTION: Iman Shumpert participates in practice as he awaits clearance to join a contact scrimmage. Photo: Anthony J. Causi

Iman Shumpert was joking the other day he’d be “thirsty’’ to have been around in the 1950s to get a chance to dunk on Bill Russell.

Today, the cocksure Shumpert may have to be content to dunk on Tyson Chandler. Knicks coach Mike Woodson said last night Shumpert had knee tests yesterday and was on the verge of being medically cleared for his first 5-on-5 contact scrimmage — the last step in his eight-month comeback from an ACL tear. The Knicks practice today and tomorrow.

If things go well, it’s not out of the realm of possibility Shumpert could make his season debut in the Knicks’ special showcase game in London against the Pistons in nine days.

* J.R. Smith sustained 11 stitches by his eyebrow after a head-to-head collision with Boston’s Avery Bradley in the final minutes. The medical staff was unable to stop Smith from bleeding during the timeout as he was ready to shoot free throws. Finally, Smith went onto the court with a headband strapped over a bandage to keep the blood from spilling. Smith missed the first free throw, but made the second.

“Don’t worry about it, I’m still breathing,’’ Smith said.

Smith finished with a team-high 24 points — his seventh straight game of 18-plus. Smith said he didn’t think the head-butt by Bradley was intentional.

* Amar’e Stoudemire played a season-high 27:50, including much of the fourth quarter. He finished with 13 points on 4-of-6 shooting but had just two rebounds and was slow at times on defense.

* Woodson said his point-guard rotation will depend on who has the hot hand. Jason Kidd played 33 minutes and Pablo Prigioni was limited to 14 minutes.